1887

Abstract

The recently identified promoter of the anaerobically inducible operon of overlaps the Fnr (fumarate-nitrate reduction regulator)-dependent promoter. The Fnr-binding site of and the -35 hexamer sequence of are shared between the promoters. Inactivation of , through introduction of a -10 hexamer mutation, resulted in enhanced anaerobic induction of operon expression. The dependence on the ArcA (aerobic respiration control regulator) and Fnr transcription factors for anaerobic induction was tested for several and gene fusions. Anaerobic induction became more dependent on Fnr in derivatives lacking a functional promoter compared with wild-type constructs. Moreover, aerobic expression of the gene was reduced by the mutation, as was the dependence on ArcA for anaerobic induction. Inactivation of severely reduced Fnr-dependent anaerobic induction, in accord with previous findings. Transcription analyses demonstrated that a mutation in the -10 hexamer sequence of either or did not adversely affect transcription from the remaining promoter. Taken together, these results indicate that the promoter moderates the Fnr-dependent activation of through competition for RNA polymerase binding.

Loading

Article metrics loading...

/content/journal/micro/10.1099/00221287-143-3-775
1997-03-01
2019-11-12
Loading full text...

Full text loading...

http://instance.metastore.ingenta.com/content/journal/micro/10.1099/00221287-143-3-775
Loading
This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error